Yep lots of warm air advection taking place - surface flow is NE and then turning to a northerly aloft.
Also the jet is in a favourable position at present.
http://forecasts.bsch.au.com/gfs_plot.h ... &mode=plot" onclick="window.open(this.href);return false;
300 jet at 5am
And again at 11am
http://forecasts.bsch.au.com/gfs_plot.h ... &mode=plot" onclick="window.open(this.href);return false;
These are favourable in terms of where the left entrance to the jet is - providing lots of upper divergence and upmotion.
Then there is the upmotion as a result of all that poleward flowing air - isentropic flow (not exactly isentropic) will result in upmotion if the air is moving poleward.
TAF TAF YMML 131022Z 1312/1418
02018G35KT 9999 RA SCT020 BKN040
FM140000 24012KT 9999 RA SCT010 BKN035
FM140600 VRB05KT 9999 FEW010 BKN045
INTER 1312/1320 3000 RA BKN010
TEMPO 1320/1404 2000 +RA BKN005
RMK FM131200 MOD/SEV TURB BLW 5000FT TILL132400
T 24 24 23 23 Q 1002 1000 999 1000
TAF AMD YMML 130443Z 1306/1412
07014KT 9999 RA SCT020 BKN035
FM131200 02018G35KT 9999 RA SCT020 BKN040
FM140000 22012KT 9999 RA SCT010 BKN035
TEMPO 1306/1312 3000 +RA BKN008
INTER 1312/1320 4000 RA BKN010
TEMPO 1320/1404 2000 +RA BKN005
PROB30 INTER 1306/1312 1000 TSRA BKN005 SCT030CB
RMK FM130600 MOD TURB BLW 5000FT TILL131200
FM131200 MOD/SEV TURB BLW 5000FT TILL132400
T 24 24 23 22 Q 1004 1003 1002 1001
TAFs above indicate the BoM think the change hasn't sped up, still expected around 11am at Tulla with the heaviest rain between 7am and 3pm.